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Manhole
A manhole (utility hole, maintenance hole, or sewer hole) is an opening to a confined space such as a shaft (civil engineering), shaft, utility vault, or large container, vessel. Manholes, typically protected by a manhole cover, are often used as an access point for an underground public utility, allowing inspection, maintenance, and system upgrades. The majority of underground services have manholes, including Water industry, water, sanitary sewer, sewers, telephone, electricity, storm drains, district heating, and natural gas, gas. Manholes are generally found in urban areas, in streets and occasionally under sidewalks. In rural and undeveloped areas, services such as telephone and electricity are usually carried on utility poles or even Electricity pylon, pylons rather than underground. In Australia, ''manhole'' also commonly refers to an access hatch used to get access from a room or hallway into the ceiling cavity of a building. These manholes are typically around square ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhole Cover
A manhole cover is a removable plate forming the lid over the opening of a manhole, an opening large enough for a person to pass through that is used as an access point for an underground vault or pipe. It is designed to prevent anyone or anything from falling in, and to keep out unauthorized persons and material. Manhole covers date back at least to the era of ancient Rome, which had sewer grates made from stone. Description Manhole covers are often made out of cast iron, concrete or a combination of the two. This makes them inexpensive, strong, and heavy, usually weighing more than . The weight helps to keep them in place when traffic passes over them, and makes it difficult for unauthorized people without suitable tools to remove them. Manhole covers may also be made from glass-reinforced plastic or other composite material (especially in Europe, or where cover theft is of concern). Because of law restricting acceptable manual handling weights, Europe has seen a move towar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhole Covers In Sidewalk (42839905802)
A manhole (utility hole, maintenance hole, or sewer hole) is an opening to a confined space such as a shaft, utility vault, or large vessel. Manholes, typically protected by a manhole cover, are often used as an access point for an underground public utility, allowing inspection, maintenance, and system upgrades. The majority of underground services have manholes, including water, sewers, telephone, electricity, storm drains, district heating, and gas. Manholes are generally found in urban areas, in streets and occasionally under sidewalks. In rural and undeveloped areas, services such as telephone and electricity are usually carried on utility poles or even pylons rather than underground. In Australia, ''manhole'' also commonly refers to an access hatch used to get access from a room or hallway into the ceiling cavity of a building. These manholes are typically around square. Construction Manhole closings are protected by a grating or manhole cover, a flat plug des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanitary Sewer
A sanitary sewer is an underground pipe or tunnel system for transporting sewage from houses and commercial buildings (but not stormwater) to a sewage treatment plant or disposal. Sanitary sewers are a type of gravity sewer and are part of an overall system called a "sewage system" or sewerage. Sanitary sewers serving industrial areas may also carry industrial wastewater. In municipalities served by sanitary sewers, separate storm drains may convey surface runoff directly to surface waters. An advantage of sanitary sewer systems is that they avoid combined sewer overflows. Sanitary sewers are typically much smaller in diameter than combined sewers which also transport urban runoff. Backups of raw sewage can occur if excessive stormwater inflow or groundwater infiltration occurs due to leaking joints, defective pipes etc. in aging infrastructure. Purpose Sewage treatment is less effective when sanitary waste is diluted with stormwater, and combined sewer overflows occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. When it is inhaled or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Despite this, the human body produces small amounts of this sulfide and its mineral salts, and uses it as a signalling molecule. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers; this process is commonly known as anaerobic digestio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaft (civil Engineering)
file:access shaft - geograph.org.uk - 6506414.jpg, A shaft equipped with ladder rungs for personnel access In civil engineering a shaft is an underground vertical or inclined passageway. Shafts are often entered through a manhole and closed by a manhole cover. They are constructed for a number of reasons including: * For the construction of a tunnel * For Ventilation (mining), ventilation of a tunnel or Subterranea (geography), underground structure, aka ventilation shaft * As a drop shaft for a sewerage or water tunnel * For access to a tunnel or underground structure, also as an escape route Construction There are a number of methods for the construction of shafts, the most significant being: * The use of sheet piles, Slurry wall, diaphragm walls or bored piles to construct a square or rectangular braced shaft * The use of segmental lining installed by underpinning or caisson (engineering), caisson sunk to form a circular shaft * Incremental excavation with a shotcret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utility Vault
A utility vault is an underground room providing access to subterranean public utility equipment, such as valves for water or natural gas pipes, or switchgear for electrical or telecommunications equipment. A vault is often accessible directly from a street, sidewalk or other outdoor space, thereby distinct from a basement of a building.City of New York, New York. ''2014 Construction Codes.'' Building Code, Chapter 32"Section 3201.8. Definitions.""Vault: Any space below the surface of a street, that is covered over, except those openings that are used exclusively as places for descending, by means of steps, to the cellar or basement of any building." Accessed 2018-04-09. Utility vaults are commonly constructed out of reinforced concrete boxes, poured concrete or brick. Small ones are usually entered through a manhole or grate on the topside and closed up by a manhole cover. Such vaults are considered confined spaces and can be hazardous to enter. Large utility vaults are simila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Gas
Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium. Methane is a colorless and odorless gas, and, after carbon dioxide, is the second-greatest greenhouse gas that contributes to global climate change. Because natural gas is odorless, a commercial odorizer, such as Methanethiol (mercaptan brand), that smells of hydrogen sulfide (rotten eggs) is added to the gas for the ready detection of gas leaks. Natural gas is a fossil fuel that is formed when layers of organic matter (primarily marine microorganisms) are thermally decomposed under oxygen-free conditions, subjected to intense heat and pressure underground over millions of years. The energy that the decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storm Drain
A storm drain, storm sewer (United Kingdom, U.S. and Canada), highway drain, surface water drain/sewer (United Kingdom), or stormwater drain (Australia and New Zealand) is infrastructure designed to drain excess rain and ground water from impervious surfaces such as paved streets, car parks, parking lots, footpaths, sidewalks, and roofs. Storm drains vary in design from small residential dry wells to large municipal systems. Drains receive water from street gutters on most motorways, freeways and other busy roads, as well as towns in areas with heavy rainfall that leads to flooding, and coastal towns with regular storms. Even rain gutters from houses and buildings can connect to the storm drain. Since many storm drainage systems are gravity sewers that drain untreated storm water into rivers or streams, any hazardous substances poured into the drains will contaminate the destination bodies of water. Storm drains sometimes cannot manage the quantity of rain that fall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grating
A grating is any regularly spaced collection of essentially identical, parallel, elongated elements. Gratings usually consist of a single set of elongated elements, but can consist of two sets, in which case the second set is usually perpendicular to the first (as illustrated). When the two sets are perpendicular, this is also known as a grid (as in grid paper) or a mesh. As filters A grating covering a drain (as illustrated) can be a collection of iron bars (the identical, elongated elements) held together (to ensure the bars are parallel and regularly spaced) by a lighter iron frame. Gratings over drains and air vents are used as filters, to block movement of large solids (e.g. people) and to allow movement of liquids. A register is a type of grating used in heating, ventilation, and air conditioning, which transmits air, while stopping solid objects. File:Vindobona Hoher Markt-71.JPG, Grating - drain cover, ancient Roman architecture at Vindobona, Austria. File:Montr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precast Concrete
Precast concrete is a construction product produced by casting concrete in a reusable molding (process), mold or "form" which is then cured in a controlled environment, transported to the construction site and maneuvered into place; examples include precast beam (structure), beams, and wall panels, floors, roofs, and piles. In contrast, cast-in-place concrete is poured into site-specific forms and cured on site. Recently lightweight expanded polystyrene foam is being used as the cores of precast wall panels, saving weight and increasing thermal insulation. Precast stone is distinguished from precast concrete by the finer construction aggregate, aggregate used in the mixture, so the result approaches the natural product. Overview Precast concrete is employed in both interior and exterior applications, from highway, bridge, and high-rise projects to parking structures, K-12 schools, warehouses, mixed-use, and industrial building construction. By producing precast concrete in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Hatch
A trapdoor or hatch is a sliding or hinged door that is flush with the surface of a floor, ceiling, or roof. It is traditionally small in size. It was invented to facilitate the hoisting of grain up through mills, however, its list of uses has grown over time. The trapdoor has played a pivotal function in the operation of the gallows, cargo ships, trains, booby traps, and more recently theatre and films. History Originally, trapdoors were sack traps in mills, and allowed the sacks to pass up through the mill while naturally falling back to a closed position. Many buildings with flat roofs have hatches that provide access to the roof. On ships, hatches—usually not flush, and never called trapdoors—provide access to the deck. Cargo ships, including bulk carriers, have large hatches for access to the holds. Gallows Most 19th- and early 20th-century gallows featured a trapdoor, usually with two flaps. The condemned was placed at the join. The edge of a trapdoor furthest f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Material
A composite or composite material (also composition material) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Composite materials with more than one distinct layer are called ''composite laminates''. Typical engineered composite materials are made up of a binding agent forming the ''matrix'' and a Filler (materials), filler material (particulates or fibres) giving ''substance'', e.g.: * Concrete, reinforced concrete and masonry with cement, lime or Mortar (masonry), mortar (which is itself a composite material) as a binder * Composite wood such as glulam and plywood with wood glue as a binder * Reinforced plastics, such as fiberglass and fibre-rein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
